McDonald's Corp. went on the offense Tuesday against critics who complain that it's a lousy place to work.

The world's largest hamburger chain held its first National Hiring Day and was awarded with a strong response from job seekers. Thousands showed up at restaurants nationwide to apply for jobs mixing shakes and serving Happy Meals. The company planned to hire 50,000 new workers in one day, boosting its staff by about 7 percent.

McDonald's painted the event as a boon for an economy where more than 13 million Americans are looking for work. But the real purpose, industry experts said, is that McDonald's needs to portray itself as a decent employer.

That will be a challenge for a company whose name is often synonymous with "you-want-fries-with-that" jokes. "McJob" even has a place in The Oxford English Dictionary, defined as "an unstimulating, low-paid job with few prospects."

But to people who need work, any stigma is beside the point.

Managers at a McDonald's in Cincinnati said a dozen or so applicants had lined up by 7 a.m., an hour before the restaurant planned to start interviews. By 10 a.m., the store had interviewed 100 people and had 25 more waiting.

Tiwian Irby, 28, was hoping for a full-time job and wasn't particular about what it would entail. He said he'd had trouble finding regular work since getting laid off from his construction job two years ago.

"A job is a job to me," said Irby, a father of three. "I'll take whatever is available."

McDonald's and other fast-food chains, once an entry point into the work force for teenagers, appear to be turning into an employer of more adults, a legacy of the recession, industry watchers said. The average age of a fast-food worker is 29.5, up from 22 in 2000, according to the U.S. Census Bureau.

Danitra Barnett, McDonald's U.S. vice president of human resources, said she couldn't specify what proportion of the 50,000 new jobs will be full-time, or what they will pay. About 90 percent of McDonald's restaurants are owned by franchisees, and the company doesn't control what they offer in wages or benefits. Barnett said most franchisees pay more than minimum wage, which is $7.25-an-hour nationally.

$7.25 an hour would amount to about $15,000 a year for a full-time worker, according to government formulas.

McDonald's said it and its franchisees will spend an additional $518 million in the coming year because of Tuesday's hiring. That amounts to just over $10,000 per new employee.

Spokeswoman Danya Proud said the company preferred to focus on the net economic benefit of the new hiring, including the money that employees will spend in their local economies.

In Senate testimony last year, McDonald's said that about 75 percent of employees at company-owned restaurants are part-time, averaging 18 hours a week. Restaurant employees tend to stay an average of 17 months, HR chief Rich Floersch testified in December.

But McDonald's also touts how its jobs can grow into bigger opportunities. According to the company, 30 percent of its executives started in restaurants, as well as more than 70 percent of restaurant managers.

Salaried managers for company-owned restaurants can make between about $32,000 and $50,000 annually, Proud said.

That's slightly less than elementary school teachers, who average $53,150, according to the Bureau of Labor Statistics. It's more than bank tellers, at $24,780. The average annual salary in the U.S. is $43,460.

McDonald's CEO Jim Skinner made $9.7 million last year.

Cortney Gatewood, 16, was looking for part-time work at a Cincinnati McDonald's on Tuesday. She said she wanted to save for college and didn't hesitate to consider the fast-food chain.

"I think it's a good place to work," Gatewood said. "I come here almost every day to eat anyway."

Though the 50,000 jobs are new, McDonald's usually staffs up for summer anyway, and it's constantly gaining and losing employees. It added 50,000 new workers in April last year, so Tuesday's blitz amounts to typical hiring, albeit compressed into a day.

With 14,000 U.S. restaurants, Tuesday's planned additions amount to about three or four new employees per restaurant — the amount that each store is probably usually looking for anyway, said Sara Senatore, an analyst at Sanford C. Bernstein.

For Richmond, Va., area franchisee Sue Durlak, National Hiring Day was an opportunity to expand the applicant pool for her 10 restaurants, and maybe even find someone who can follow in her footsteps.

She started part-time in 1982 while working as a middle-school health teacher in Illinois to supplement her income. She has since worked her way up to owning several locations.

"I do look at anyone who applies, as well as the rest of my team, as the potential as a lifer," Durlak said.